Disklavier

Yes, it's very likely you need to have the damper pedal properly adjusted and then have the pedal calibrated. 

I recommend you have it done by Professional Disklavier Technician . 

On the Mark IV there is an option in the Service Center's extended menu.

Option 2) Disklavier Piano System
Then
Option 3) Plano Calibration - Full/
Then
Option 6) Petal-HP Adjustment

This tool will allow the tech to adjust where the Disklavier system thinks the Damper's Half Pedal sweet spot is to where it actually is. If that makes since...

Best of luck! 

Ken